If I use a expensive commercial software I can read the data but I did not buy it because it is too expensive for me. Since I have the conviction that I do not reformat the hard drive again and I can read the data easily.
I am about to do the following:
- Read Data of 2 disks (out of 4 disk Raid 10 hardware array) physically moved into Linux Desktop PC.
- looking for a software RAID solution that can do that. I hope mdadm can do that.
Creating the Raid works:
# mdadm --create /dev/md/md_27tb --level=0 --raid-devices=2 /dev/sdf2 /dev/sdd2
mdadm: /dev/sdf2 appears to be part of a raid array:level=raid10 devices=4 ctime=Sun Nov 3 01:19:11 2019
mdadm: /dev/sdd2 appears to be part of a raid array:level=raid10 devices=4 ctime=Sun Nov 3 01:19:11 2019
Continue creating array? y
mdadm: Defaulting to version 1.2 metadata
mdadm: array /dev/md/md_27tb started.
Unfortunately, I was unable to read the data. Not possible to mount.
then I read: mount: wrong fs type, bad option, bad superblock and tried:
# mount -t ext4 /dev/md/md_27tb /mnt/md_27tb
mount: /mnt/md_27tb: wrong fs type, bad option, bad superblock on /dev/md126, missing codepage or helper program, or other error.
# fsck /dev/md/md_27tb
# fsck /dev/md/md_27tb
fsck from util-linux 2.34
e2fsck 1.45.4 (23-Sep-2019)
ext2fs_open2: Bad magic number in super-block
fsck.ext2: Superblock invalid, trying backup blocks...
fsck.ext2: Bad magic number in super-block while trying to open /dev/md126
The superblock could not be read or does not describe a valid ext2/ext3/ext4
filesystem. If the device is valid and it really contains an ext2/ext3/ext4
filesystem (and not swap or ufs or something else), then the superblock
is corrupt, and you might try running e2fsck with an alternate superblock:
e2fsck -b 8193 <device>
or
e2fsck -b 32768 <device>
# e2fsck -b 32768 /dev/md/md_27tb
e2fsck: Bad magic number in super-block
# e2fsck -b 8193 /dev/md/md_27tb
e2fsck: Bad magic number in super-block
Maybe i used the wrong file system.
I read here:
Maybe its ext3?
UPDATE important informations:
# file -sk /dev/md/md_27tb
/dev/md/md_27tb: symbolic link to ../md126
# fdisk -l /dev/md/md_27tb
Disk /dev/md/md_27tb: 5.43 TiB, 5957897682944 bytes, 11636518912 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 4096 bytes
I/O size (minimum/optimal): 524288 bytes / 1048576 bytes
# file -skL /dev/md/md_27tb
/dev/md/md_27tb: data
UPDATE important informations:
vgscan scans all supported LVM block devices in the system for VGs.
# vgscan
Reading volume groups from cache.
Found volume group "md0_vg" using metadata type lvm2
# pvscan
PV /dev/md127 VG md0_vg lvm2 [19.98 GiB / 0 free]
Total: 1 [19.98 GiB] / in use: 1 [19.98 GiB] / in no VG: 0 [0 ]
# vgdisplay
- Volume group -
VG Name md0_vg
System ID
Format lvm2
Metadata Areas 1
Metadata Sequence No 3
VG Access read/write
VG Status resizable
MAX LV 0
Cur LV 2
Open LV 0
Max PV 0
Cur PV 1
Act PV 1
VG Size 19.98 GiB
PE Size 4.00 MiB
Total PE 5115
Alloc PE / Size 5115/19.98 GiB
Free PE / Size 0/0
VG UUID fYicLg-jFJr-trfJ-3HvH-LWl4-tCci-fI
UPDATE Wed, Nov. 27, 22:30
After a very long time of automatic reconstruction, after about one day on Wed, Nov. 27, 22:30, I get the message "Data protection reconstruction has completed." Now I am sure that the data is correct again on these two discs and I can continue to try.
# mdadm --assemble --force /dev/md/md_27tb /dev/sdf2 /dev/sdd2
mdadm: /dev/sdf2 is busy - skipping
mdadm: /dev/sdd2 is busy - skipping
[seeh-pc seeh]#
UPDATE 191128-090222 (By the way: sde is certainly not of interest here): I would prefer md126 would not be there.
$ lsblk
....
sdd 8:48 0 2.7T 0 disk
├─sdd1 8:49 0 20G 0 part
│ └─md126 9:126 0 20G 0 raid1
│ ├─md0_vg-BFDlv
│ │ 253:0 0 4G 0 lvm
│ └─md0_vg-vol1
│ 253:1 0 16G 0 lvm
└─sdd2 8:50 0 2.7T 0 part
sde 8:64 0 931.5G 0 disk
├─sde1 8:65 0 60.6G 0 part
└─sde2 8:66 0 871G 0 part
sdf 8:80 0 2.7T 0 disk
├─sdf1 8:81 0 20G 0 part
│ └─md126 9:126 0 20G 0 raid1
│ ├─md0_vg-BFDlv
│ │ 253:0 0 4G 0 lvm
│ └─md0_vg-vol1
│ 253:1 0 16G 0 lvm
└─sdf2 8:82 0 2.7T 0 part
UPDATE 191128-123821: raid1 looks wrong for me:
$ cat /proc/mdstat
Personalities : [raid1]
md126 : active (auto-read-only) raid1 sdd1[0] sdf1[2]
20955008 blocks super 1.1 [2/2] [UU]
md127 : inactive sdd2[6](S) sdf2[7](S)
5818261504 blocks super 1.1
UPDATE 191128-144807 :
Is looks like a success.
# mdadm --assemble --force /dev/md127 /dev/sdf2 /dev/sdd2
mdadm: /dev/sdf2 is busy - skipping
mdadm: /dev/sdd2 is busy - skipping
[seeh-pc seeh]# mdadm --stop md127
mdadm: stopped md127
[seeh-pc seeh]# mdadm --assemble md127 --run /dev/sdf2 /dev/sdd2
mdadm: /dev/md/md127 has been started with 2 drives (out of 4).
[seeh-pc seeh]#
# cat /proc/mdstat
Personalities : [raid1] [raid10]
md1 : active raid10 sdd2[6] sdf2[7]
5818260480 blocks super 1.1 512K chunks 2 near-copies [4/2] [_U_U]
md126 : active (auto-read-only) raid1 sdd1[0] sdf1[2]
20955008 blocks super 1.1 [2/2] [UU]
sdd 8:48 0 2.7T 0 disk
├─sdd1 8:49 0 20G 0 part
│ └─md126 9:126 0 20G 0 raid1
│ ├─md0_vg-BFDlv
│ │ 253:0 0 4G 0 lvm
│ └─md0_vg-vol1
│ 253:1 0 16G 0 lvm
└─sdd2 8:50 0 2.7T 0 part
└─md1 9:1 0 5.4T 0 raid10
└─3760fd40_vg-lv2111e672
253:2 0 5.4T 0 lvm
sde 8:64 0 931.5G 0 disk
├─sde1 8:65 0 60.6G 0 part
└─sde2 8:66 0 871G 0 part
sdf 8:80 0 2.7T 0 disk
├─sdf1 8:81 0 20G 0 part
│ └─md126 9:126 0 20G 0 raid1
│ ├─md0_vg-BFDlv
│ │ 253:0 0 4G 0 lvm
│ └─md0_vg-vol1
│ 253:1 0 16G 0 lvm
└─sdf2 8:82 0 2.7T 0 part
└─md1 9:1 0 5.4T 0 raid10
└─3760fd40_vg-lv2111e672
253:2 0 5.4T 0 lvm
